The present invention relates to meat analogs and more particularly, relates to a method and apparatus for forming meat analog products.
Meat analog products are well known in the art and there have been various methods and apparati proposed for preparing such products. The meat analog products are frequently used as substitutes for natural meat products as they consist of all-vegetable materials, may contain fewer fat calories and have a lower cholesterol content. However, in order to obtain consumer acceptance, the visual appearance and the texture of the products must meet certain standards. To date, this has been difficult to do leading to the situation that, although one can manufacture products which have certain superior properties such as nutritional value, the various sensory properties desired have not been achieved for a product which can be manufactured on a commercial scale.
Originally, the formation of meat analog products relied on the use of fiber spinning wherein a spinning dope is formed from alkali treated protein with the dope subsequently being extruded through a die or membrane into an aqueous precipitant bath which sets the filaments or fibers. Also known in the art are thermoplastic extrusion techniques to form certain products where a mixture of protein, water and flavor ingredients is fed into a cooker extruder and subsequently released into the atmosphere.
Various attempts have been made in the past years to arrive at a more consumer acceptable product and techniques have included the forming of a dough which is then subjected to stretching and heat to provide uni-directional parallel meat like fibers. Although such processes have been described since the 1960's, applicant is not aware of products being produced on a commercial scale utilizing this technology. Such technology has been described, for example, in U.S. Pat. Nos. 3,693,533; 3,814,823; 4,125,635; and 4,910,040. In the last mentioned patent, the patentee discloses a method for preparing food products having aligned fibers wherein a protein source and a carbohydrate source are mixed, forced through a first passageway having a constant cross-sectional area, pushed through a second passageway having a decreasing cross-sectional area, and then pushed through a third passageway with a constant cross-sectional area, and heating the fibers in the third section to fix or set the fibers in a linearly aligned configuration.
While there are different theories as to how and why the fibers form, it has been well established that there does indeed exist fiber formation as a result of mixing the required ingredients along with the application of heat and stretching. However, the methods and apparatuses for the production of such meat analog products have generally tended to exist only in laboratory type apparatuses and to date, to the best of applicant's knowledge, there does not exist a system capable of sufficient throughput to become commercially viable. It is believed that this lack of commercial success is due to the inability to scale up from laboratory type of systems to systems which are capable of producing commercial quantities.